(1) Field of the Invention
This invention relates to templets for making pattern cuts in pipe with a torch. Applicant designates one with ordinary skill in the art to be a welder or other person skilled in cutting metal pipe with a gas fed torch.
(2) Description of the Prior Art
When joining lengths of pipe by welding it is often necessary to cut the ends to be joined in a specific pattern. One example is cutting 45 degree angles in pipe ends to be welded together to form an elblow or right angle joint. Another example, when a pipe length is to be welded mediate another pipe, such as for a tee or to interconnect parallel pipes of a framework, is to cut a saddle pattern in the pipe end. Still another example for closing an end of a pipe is to cut an orange peel pattern, bend the splayed ends inward, and welded the "peels" together.
Before my invention, workers in the art used plastic or steel templets for drawing the patterns on pipe with chalk, soapstone, grease pencil, or the like. While holding and guiding the torch entirely with the hands, the cutting tip was traced along the mark on the pipe. Inevitably, errors in marking and difficulty in manipulating the pipe and templet together frequently resulted in inaccurate cuts.
Users of prior art templets also had problems with the slag from the cut away metal collecting on the finished, retained workpiece. The slag had to be knocked off with a hammer or chisel. Additionally, to follow the pattern mark on the pipe, the torch was moved with the cutting axis or flame radial of the pipe, requiring frequent rotation of the workpiece.
Before filing this invention, a search was made in the United States Patent and Trademark Office, which search developed the following United States patents:
CARR, U.S. Pat. No. 1,683,953 PA1 GOTTWALD, U.S. Pat. No. 2,155,705 PA1 ENDERSON, U.S. Pat. No. 2,326,447 PA1 HOWARD, U.S. Pat. No. 2,408,517 PA1 LEE, 2,985,963 PA1 BRUNER, 4,381,854 PA1 RUSK, 4,414,041
Although these references do not appear to directly pertain to the invention, they are nevertheless cited because as the results of a search conducted by an experienced searcher, they might be regarded as relevant and pertinent to the examination of this application.